Epidemiology studies have shown that recreational exposure from swimming or surfing in locations impacted by contaminated storm water leads to a significant increase in a variety of illnesses (Griffin, 2003, supra; Haile et al. (1999) Epidemiology 10:355-363). There can be even greater potential exposure through the consumption of contaminated shellfish due to concentration of contaminants by the filter feeders (Gerba (1988) Food Technol. 42:99-103; Griffin, 2003, supra; Pina et al. (1998) Appl. Environ. Microbiol. 64:3376-3382; Schwab et al. (1998) J. Food Prot. 61:1674-1680). The illnesses of concern include (but are not limited to) diarrhea, ocular and respiratory infection, gastroenteritis, hepatitis, myocarditis, meningitis, paralysis, and severe chronic disease.
In the United States, Escherichia coli and enterococci are currently used as indicators of microbial water quality, serving as proxies for the potential presence of pathogenic bacteria and viruses.
Previous health and epidemiological studies by the US Environmental Protection Agency (US EPA) have demonstrated that colony-forming unit (CFU) densities of the bacterial genus Enterococcus in both marine and freshwater samples are directly correlated with gastroenteritis illness rates in swimmers exposed to these waters (Cabelli et al. (1982) J. Epidemiol. 115:606-616; Dufour (1984) EPA-600/1-84-004, Office of Research and Development, US Environmental Protection Agency, Cincinnati, Ohio). The strains commonly called E. coli can cause different infections in man or in animals according to the provision with pathogenic genes (urinary infections, choleriform or hemorrhagic diarrhea, dysentery syndrome, hemolytic and uremic syndrome, septicemia, neonatal meningitis, various purulent infections). Based on these data, guidance has been issued on the maximum concentrations of these organisms that may be associated with acceptable health risks (Dufour and Ballantine (1986) EPA 440/5-84-002, Washington D.C.). Since then an improved, selective culture method has been developed for measuring Enterococcus concentrations in recreational water samples have shown that changes in water quality conditions during this delay period can frequently lead to notifications to the public that are not fully protective of swimmer health (Messer and Dufour (1998) Appl. Environ. Microbiol. 64:678-680; US EPA (2002) EPA 821/R-02/022, 2002, US Environmental Protection Agency, Office of Water (4303T), Washington D.C.). However, this method still requires at least 24 hours to obtain results.
Increasing interest is now being directed towards the possible use of molecular microbial analysis methods with shorter reporting times. One such technology is the quantitative polymerase chain reaction (QPCR). Primer sets and probes associated with this technology have now been developed for the specific detection of a number of different fecal indicator organisms and waterborne pathogens (Ludwig and Schleifer (2000) Syst. Appl. Microbiol. 23:556-562; Lyon (2001) Appl. Environ. Microbiol. 67:4685-4693; Brinkman et al. (2003) Appl. Environ. Microbiol. 69:1775-1782; Foulds et al. (2002) J. Appl. Microbiol. 93:825-834; Blackstone et al. (2003) J. Microbiol. Methods 53:149-155; Frahm and Obst (2003) J. Microbiol. Methods 52:123-131; Guy et al. (2003) Appl. Environ. Microbiol. 69:5178-5185; Noble et al. (2003) J. Water Health 1: 195-207). The availability of portable instrumentation that can be operated at or near the site and the development of rapid methods for processing samples for QPCR analysis (Brinkman et al. 2003, supra) have reduced the potential overall time requirements of this method to a matter of only a few hours, from sampling to results.
Several patents disclose methods to detect harmful bacteria. U.S. Pat. No. 6,207,818, U.S. Pat. No. 6,060,252, U.S. Pat. No. 6,054,269 and U.S. Pat. No. 5,298,392 all describe the amplification and detection of such harmful bacteria.
There is a vital need for rapid methods to quantify indicator bacteria in biological, industrial, and environmental samples that yield equivalent results to existing methods. Additional methods are needed to rapidly detect the presence of harmful bacteria in biological, industrial, and environmental samples.